iconv/gconv_open.c

   1 /* Find matching transformation algorithms and initialize steps.
   2    Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <gconv_int.h>
  26
  27
  28 int
  29 internal_function
  30 __gconv_open (const char *toset, const char *fromset, __gconv_t *handle,
  31               int flags)
  32 {
  33   struct __gconv_step *steps;
  34   size_t nsteps;
  35   __gconv_t result = NULL;
  36   size_t cnt = 0;
  37   int res;
  38   int conv_flags = 0;
  39   const char *runp;
  40
  41   /* Find out whether "IGNORE" is part of the options in the `toset'
  42      name.  If yes, remove the string and remember this in the flag.  */
  43   runp = __strchrnul (__strchrnul (toset, '/'), '/');
  44   if (strcmp (runp, "IGNORE") == 0)
  45     {
  46       /* Found it.  This means we should ignore conversion errors.  */
  47       char *newtoset = (char *) alloca (runp - toset + 1);
  48
  49       newtoset[runp - toset] = '\0';
  50       toset = memcpy (newtoset, toset, runp - toset);
  51
  52       flags = __GCONV_IGNORE_ERRORS;
  53     }
  54
  55   res = __gconv_find_transform (toset, fromset, &steps, &nsteps, flags);
  56   if (res == __GCONV_OK)
  57     {
  58       /* Allocate room for handle.  */
  59       result = (__gconv_t) malloc (sizeof (struct __gconv_info)
  60                                    + (nsteps
  61                                       * sizeof (struct __gconv_step_data)));
  62       if (result == NULL)
  63         res = __GCONV_NOMEM;
  64       else
  65         {
  66           /* Remember the list of steps.  */
  67           result->__steps = steps;
  68           result->__nsteps = nsteps;
  69
  70           /* Clear the array for the step data.  */
  71           memset (result->__data, '\0',
  72                   nsteps * sizeof (struct __gconv_step_data));
  73
  74           /* Call all initialization functions for the transformation
  75              step implementations.  */
  76           for (cnt = 0; cnt < nsteps - 1; ++cnt)
  77             {
  78               size_t size;
  79
  80               /* Would have to be done if we would not clear the whole
  81                  array above.  */
  82               /* If this is the last step we must not allocate an
  83                  output buffer.  */
  84               result->__data[cnt].__flags = conv_flags;
  85
  86 #if 0
  87               /* Reset the counter.  */
  88               result->__data[cnt].__invocation_counter = 0;
  89
  90               /* It's a regular use.  */
  91               result->__data[cnt].__internal_use = 0;
  92 #endif
  93
  94               /* We use the `mbstate_t' member in DATA.  */
  95               result->__data[cnt].__statep = &result->__data[cnt].__state;
  96
  97               /* Allocate the buffer.  */
  98               size = (GCONV_NCHAR_GOAL * steps[cnt].__max_needed_to);
  99
 100               result->__data[cnt].__outbuf = (char *) malloc (size);
 101               if (result->__data[cnt].__outbuf == NULL)
 102                 {
 103                   res = __GCONV_NOMEM;
 104                   break;
 105                 }
 106               result->__data[cnt].__outbufend =
 107                 result->__data[cnt].__outbuf + size;
 108             }
 109
 110           /* Now handle the last entry.  */
 111           result->__data[cnt].__flags = conv_flags | __GCONV_IS_LAST;
 112           /* Would have to be done if we would not clear the whole
 113              array above.  */
 114 #if 0
 115           result->__data[cnt].__invocation_counter = 0;
 116           result->__data[cnt].__internal_use = 0;
 117 #endif
 118           result->__data[cnt].__statep = &result->__data[cnt].__state;
 119         }
 120
 121       if (res != __GCONV_OK)
 122         {
 123           /* Something went wrong.  Free all the resources.  */
 124           int serrno = errno;
 125
 126           if (result != NULL)
 127             {
 128               while (cnt-- > 0)
 129                 free (result->__data[cnt].__outbuf);
 130
 131               free (result);
 132               result = NULL;
 133             }
 134
 135           __gconv_close_transform (steps, nsteps);
 136
 137           __set_errno (serrno);
 138         }
 139     }
 140
 141   *handle = result;
 142   return res;
 143 }